Tóm tắt

The biocompatibility, flexibility, and tissue-like mechanical properties of hydrogels suggest they are promising rnmaterials for wearable devices. However, the production of smart, self-healing hydrogels is limited by the un-stable structure of load-bearing stressors and the need for long-term healing capacity. An important goal when rndeveloping such hydrogels is to improve their mechanical characteristics and rapid ability to self-repair in rnphysiological environments. In this study, we aimed to create a thermo-responsive hydrogel that possessed rnthermal-healing and enhanced mechanical properties, without losing its self-healing capabilities, by employing rntwo interpenetrating cross-linked networks of polyvinyl alcohol (PVA) and boron nitride nanosheets (BNNSs). rnWe observed that addition of BNNSs significantly increased the glass transition temperature (Tg) and tem-perature-dependent swelling of PVA hydrogels, indicating a high compatibility between these two materials and rna high thermal response to external stimuli. Our results suggest that PVA hydrogels combined with BNNSs rnoutperform single-network PVA hydrogels in terms of thermal-healing capacity. As above Tg, the thermal energy rngained during moisture loss leads to an increase in the thermal mobility of the polymer chains and in the free rnvolume available for new hydrogen bonds at the fracture surface. This unique structure increases water content rnand confers better mechanical properties. Interestingly, this structure of the second network benefits the first rnPVA network during deformation by effectively dissipating energy and bearing force, and contrarily to single- rnnetwork PVA hydrogels. Taken together, our results show that combining PVA and BNNSs to create a hybrid rnstructure, exerts a synergistic effect and successfully improves the thermal-healing performance of wet hydro-gels.